the success of Juju deployments. It gives you a structured means of having an
entirely repeatable deployment process, specifically going from an entirely
empty environment with no VMs running to VMs with the services deployed
on them, relationships established between them, and a fully working service.
More information is available at https://mojo.canonical.com.
Ubuntu Core
Ubuntu Core is a minimalistic Ubuntu installation with transactional updates.
It is a bare-bones server image with the same libraries as regular Ubuntu.
However, applications are installed in a new way. The idea is that applications
are deployed in an encapsulated way, as Snap packages, such that a change to
one application cannot affect any other applications. This provides more
predictable behavior and stronger security. Application updates come as
“delta updates,” which means only the changes are downloaded and installed,
leading to smaller downloads and faster upgrades. See Chapter 9, “Managing
Software,” to learn how to use Snap packages; Chapter 41, “Using Ubuntu for
Opportunistic Software Development,” for information about creating Snap
packages of existing software; and www.ubuntu.com/core for more.
Ubuntu Metal as a Service (MaaS)
Juju exists to deploy workloads to the cloud. Ubuntu MaaS is built as a first
step in deploying that cloud, when you are creating the cloud on hardware
you own or over which you have bare-metal configuration control. Ubuntu
MaaS is a collection of best practices for deploying Ubuntu servers from
Ubuntu servers. It is designed to assist with deployments to cloud servers
numbering in the dozens, hundreds, or even thousands. You install Ubuntu
MaaS directly to bare metal on one server, and from there all other bare-metal
servers are provisioned and set up; an entire data center could be implemented
quickly and easily. After it’s deployed, Ubuntu MaaS provides automatic
federation and integrated management, monitoring, and logging. You can add
physical equipment, remove it, repurpose it within your cloud, and more. You
can do this dynamically, scaling up or down, and managing resources as
needed. It is powerful and very cool.
This is all done from the standard Ubuntu Server install CD, which you can
create as described in Chapter 1, “Installing Ubuntu and Post-Installation
Configuration,” except that you want the Server version instead of the regular
version of Ubuntu. At the time of this writing, the Ubuntu community is still
creating documentation for Ubuntu MaaS; see